I have an array that I'm retrieving from an API. The array looks like this:
[{
"name": "Rachel",
"count": 4,
"fon": "46-104104",
"id": 2
},
{
"name": "Lindsay",
"count": 2,
"fon": "43-053201",
"id": 3
},
{
"name": "Michael",
"count": 5,
"fon": "46-231223",
"id": 4
}]
Then I loop through the array to create an array containing only the names.
function buildName(data) {
for (var i = 0; i < data.length; i++) {
nameList.push(data[i].name)
}
}
This also works so far, but I would like to create an array in which each name occurs as often as the object count says.
For example, the name Michael should appear five times in the array and Lindsay twice.
[
"Rachel",
"Rachel",
"Rachel",
"Rachel",
"Lindsay",
"Lindsay",
"Michael",
"Michael",
"Michael",
"Michael"
"Michael"
]
For each object create a new array using count, and then fill it with the name.
If you use flatMap to iterate over the array of objects. It will return a new array of nested objects but then flatten them into a non-nested structure.
const data=[{name:"Rachel",count:4,fon:"46-104104",id:2},{name:"Lindsay",count:2,fon:"43-053201",id:3},{name:"Michael",count:5,fon:"46-231223",id:4}];
const out = data.flatMap(obj => {
return new Array(obj.count).fill(obj.name)
});
console.log(out);Use an inner while loop inside the for loop:
const data = [{
"name": "Rachel",
"count": 4,
"fon": "46-104104",
"id": 2
},
{
"name": "Lindsay",
"count": 2,
"fon": "43-053201",
"id": 3
},
{
"name": "Michael",
"count": 5,
"fon": "46-231223",
"id": 4
}]
function buildName(data){
const result = [];
for (let i = 0; i < data.length; i += 1) {
let item = data[i];
let count = item.count;
while (count > 0) {
result.push(item.name);
count -= 1;
}
}
return result;
}
console.log(buildName(data));You can use .flapMap() for that:
const arr = [{ "name": "Rachel", "count": 4, "fon": "46-104104", "id": 2 }, { "name": "Lindsay", "count": 2, "fon": "43-053201", "id": 3 }, { "name": "Michael", "count": 5, "fon": "46-231223", "id": 4 }];
const result = arr.flatMap(({count, name}) => Array(count).fill(name));
console.log(result);Effectively you turn every element into an array of the the name property repeated count times which is then flattened into a single array.